Evaluation of the Circles Measurement and the ABC Classification of Acromioclavicular Joint Injuries

Glenoid-based reference system to differentiate shoulder pathologies on plain radiographs

BACKGROUND

Shoulder radiographs are used for evaluation and the planning of treatment of various pathologies. Making a diagnosis of these pathologies on plain radiographs occurs by recognizing the relationship of the humeral head on the registry of the glenoid. Quantification of these changes in registry does not currently exist. We hypothesize that a geometric relationship of the humeral head and the glenoid exists that is defined on an anteroposterior Grashey view radiograph by the relationship of the best-fit circle of the humeral head relative to the best-fit circle of the glenoid such that relative measurements will define the normal shoulder and the pathologic shoulder.

METHODS

One hundred fifty-six shoulders were included: 53 normal shoulders, 51 with primary glenohumeral osteoarthritis (GHOA), and 52 with cuff tear arthropathy (CTA). Humeral head best-fit circle was used to define the circle of the humeral head (cHH). A glenoid best-fit circle (cG) was defined by the following rules: (1) best fit of the glenoid articular surface and (2) was limited by the acromion such that either (a) it reaches maximal interaction with the inferior surface of the acromion or (b) the perimeter of the circle is at the lateralmost point of the acromion. The relationship between cHH and cG is defined by measurement of cHH in horizontal and vertical planes relative to the glenoid circle reference. The horizontal displacement angle (HDA) measures the horizontal position of cHH relative to cG, representing the degree of medialization toward the glenoid. The vertical displacement angle (VDA) measures the vertical position of cHH relative to cG, representing the degree of superiorization toward the acromion. Angles were compared by diagnosis and sex.

RESULTS

The mean HDA was 61.0° (95% confidence interval [CI] 60.3°-61.7°) in normal shoulders, 79.9° (95% CI 76.9°-82.9°) in GHOA, and 63.4° (95% CI 61.7°-65.1°) in CTA (P < .001). The mean VDA was 43.1° (95% CI 42.2°-44.0°) in normal shoulders, 40.9° (95% CI 39.9°-42.0°) in GHOA, and 59.7° (95% CI 57.6°-61.7°) in CTA (P < .001). Interobserver reliability was 0.991 (95% CI 0.94-1.0) and intraobserver reliability was 0.998 (95% CI 0.99-1.0). The geometric relationship of cHH to the glenoid circle reference was plotted for each group.

CONCLUSION

A geometric relationship exists of the humeral head in reference to the glenoid circle. Together, the HDA and the VDA distinguish between a normal shoulder and those with GHOA or CTA. This suggests that this novel methodology may provide a preoperative planning tool that is easily accessible.

The V angle compliments radiographic assessment of acute acromioclavicular joint dislocations by differentiating between Rockwood types III versus V and by considering dynamic horizontal translation in coronal radiographs

PURPOSE

Acromioclavicular joint (ACJ) dislocations are usually graded radiographically according to Rockwood, but differentiation between Rockwood types III and V may be ambiguous. The potentially clinically relevant horizontal instability is barely addressed in coronal radiographs. It was hypothesized that a new radiologic parameter (V angle) would complement ACJ diagnostics on anteroposterior radiographs by differentiating between cases of Rockwood III and V while also considering the aspect of dynamic horizontal translation (DHT).

METHODS

Ninety-five patients with acute ACJ dislocations (Rockwood types III and V) were included retrospectively between 2017 and 2020. On anteroposterior views (weightbearing: n = 62, non-weight-bearing: n = 33), the coracoclavicular (CC) distance and the newly introduced V angle for assessing scapular orientation were measured bilaterally. This angle is referenced between the spinal column and a line crossing the superior scapular angle and the crossing point between the supraspinatus fossa and the medial base of the coracoid process, reported as the side-comparative difference (non-injured side *minus* injured side). DHT on Alexander views was divided into stable, partially unstable or completely unstable.

RESULTS

The V angle on the injured side alone (mean 50.0°; 95% confidence interval (CI), 48.6°-51.3°) showed no correlation with the side-comparative CC distance [%] (r = - 0.040; n.s.). Thus, the V angle on the non-injured side was considered, displaying a normal distribution (n.s.) with a mean of 58.0° (95% CI, 56.6°-59.4°). The side-comparative V angle showed a correlation with the side-comparative CC distance (r = 0.83; p < 0.001) and was able to differentiate between Rockwood types III (4.7°; 95% CI, 3.9°-5.5°; n = 39) and V (10.3°; 95% CI, 9.7°-11.0°; n = 56) (p < 0.001). A cut-off value of 7° had a 94.6% sensitivity and an 82.1% specificity (area under curve, AUC: 0.954; 95% CI, 0.915-0.994). The side-comparative V angle was greater for cases with complete DHT (8.7°; 95% CI, 7.9°-9.5°; n = 78) than for cases with partial DHT (4.8°; 95% CI, 3.3°-6.3°; n = 16) (p < 0.001). A cut-off value of 5° showed a sensitivity of 84.6% and a specificity of 66.7% (AUC 0.824; 95% CI, 0.725-0.924).

CONCLUSION

The scapular-based V angle on anteroposterior radiographs distinguishes between Rockwood types III and V as well as cases with partial or complete DHT.

STUDY DESIGN

Diagnostic study.

LEVEL OF EVIDENCE

Level II.

Editorial Commentary: Acute Treatment Including Cerclage Result in Best Surgical Outcomes for High-Grade Acromioclavicular Joint Separations

Despite years of research, optimal treatment of acute high-grade acromioclavicular joint (ACJ) separations remains controversial. ACJ separations occur in a "multiplanar" fashion and identification of horizonal plane instability is paramount to differentiate between high-grade versus low-grade injuries. As surgeons, we treat a self-selected group of patients referred for surgery, and our physiotherapy colleagues may rehabilitate many patients with both "low-grade" and "high-grade" separations who compensate. Of importance, ACJ separations stabilized <3 weeks after injury have the best chance of healing in a close-to anatomic position. The addition of the ACJ cerclage augmentation improves horizontal plane stability while the soft tissues heal and likely improves outcome.

[Minimally Invasive Techniques for the Treatment of Acute and Chronic Acromioclavicular Joint Instabilities]

Acromioclavicular joint instabilities are one of the most common injuries of the shoulder girdle. Diagnostic measures include the vertical and horizontal components of instability. The main goals of treatment include pain reduction, joint stabilization, and return to physical activity. For operative treatment, there are numerous techniques available. Recently, minimally-invasive techniques were developed and showed equal results as with open approach. These procedures facilitate simultaneous treatment of concomitant shoulder lesions and reduce soft tissue trauma as well as the risk of infection. This article presents an overview of such minimally-invasive techniques for both acute and chronic instabilities. Both techniques address the aspect of horizontal instability, which was found to compromise clinical results. For an acute injury, we describe the use of a low-profile button system combined with an additional acromioclavicular cerclage. In the chronic setting with a bidirectional (vertical and horizontal) instability, a free tendon graft combined with a single TightRope augmentation is recommended.

Konservative Therapie von Verletzungen des Akromioklavikulargelenks

Niedriggradige Verletzungen (Grad I und II nach Rockwood) des Akromioklavikulargelenks (ACG) können in den meisten Fällen mit gutem Outcome konservativ behandelt werden. Hierbei gibt es keine Methode der Immobilisation, welche sich als Überlegen herausgestellt hätte. Höhergradige Verletzungen (Grad IV und V), welche eine relevante Instabilität und konsekutiv häufig eine Dyskinesie des skapulothorakalen Rhythmus zur Folge haben, profitieren von einer chirurgischen Rekonstruktion. Kein Konsens trotz breiter akademischer Diskussion besteht bei Grad-III-Verletzungen. In Langzeitstudien und im Rahmen von Metaanalysen zeigten sich keine Vorteile eines operativen Vorgehens gegenüber der konservativen Behandlung nach 1 bis 2 Jahren, während einzelne Fallserien Vorteile in der anatomischen Rekonstruktion aufzeigten, insbesondere wenn für das ACG spezifische Outcome-Scores verwendet wurden. In Grenzfällen sollte das individuelle Arbeits- und Sportprofil, insbesondere regelmäßige Überkopfaktivität, in die therapeutische Entscheidungsfindung einfließen. Sowohl bei niedrig- wie auch hochgradigen Verletzungen des ACG kann durch eine fokussierte Therapie zur Verbesserung der skapulothorakalen Mobilität und Stabilität eine Skapuladyskinesie in vielen Fällen (gelegentlich auch ≥ Grad III nach Rockwood) vermieden oder erfolgreich behandelt werden.

Sports Medicine Image Modeling for Injury Prevention in Basketball Training

In order to solve the problem of sports medical image in basketball training, a sports medical image modeling research method based on injury prevention in basketball training was proposed. By the method, the current situation of sports injury in university basketball was investigated. At the same time, the injury factors were analyzed on four occasions, including basketball class, extracurricular activities, competition, and training. In order to reduce the occurrence of injury and enhance the security of basketball sports for nonbasketball students of physical education, combined with the problems and reasons, the corresponding suggestions were put forward. Through the experiment, it was found that the incidence of basketball injury for nonbasketball male university students was as high as 90.7%. The results of the experiment showed that it was necessary to enhance the awareness of self-protection, control emotions and exhibitionism, strengthen physical training, attach importance to basic skills training, do warm-up activities, stay focused, pay attention to exercise load, and prevent excessive fatigue.

Fixation of distal clavicle fractures with coracoclavicular instability: a comparative biomechanical study in human cadavers

Background

The need for coracoclavicular (CC) stabilization in the fixation of fractures with CC instability (Neer type IIB and V) was biomechanically demonstrated by higher construct strength than isolated locking plate osteosynthesis. It was the purpose of this study to prove noninferiority of the new cow-hitch suture repair technique compared with the well-established suture tape double-button fixation with regard to overall fixation strength and cyclic loading properties.

Methods

Twelve human cadaver shoulders (7 right and 5 left) were matched for sex and age (mean age: 75 ± 5 years). An oblique parasagittal fracture line 20 mm medial to the acromioclavicular joint line was created, and the CC ligaments were dissected. Six shoulders were reconstructed by a double FiberTape fixation with two suture buttons (group DB), and the remaining six shoulders by a cow-hitch suture repair using a double FiberWire with only coracoid button fixation (group CH). Both reconstruction techniques were tested in a servo-hydraulic material testing machine for cyclic displacement (mm), stiffness (N/mm), and maximum load-to-failure (N) after 500 cycles at 3 mm/s and inferosuperior load between 15 and 70 N. Superior fragment displacement in space was recorded using a MicroScribe digitizer.

Results

There were no statistically significant differences regarding cyclic displacement (group DB: 0.7 mm; group CH: 1.3 mm; P = .36), stiffness (group DB: 177 N/mm; group CH: 116 N/mm; P = .17), maximum load-to-failure (group DB: 560 N; group CH: 492 N; P = .59), and superior displacement in space of the medial fragment (group DB: 3.2 mm; group CH: 1.6 mm; P = .48).

Conclusion

Fixation of unstable distal clavicle fractures using a double FiberWire cow-hitch suture repair with isolated coracoid button fixation for stand-alone CC stabilization resulted in similar biomechanical properties to a double-suture button fixation with FiberTapes while avoiding prominent clavicular implants.